Sony a7s III ‘Dual Native ISO’

It was Gerald Undone who ‘discovered’ that the a7s III image suddenly became much cleaner when jumping from ISO 12800 to 16000 in S-log. Sony informed Philip Bloom that the point at which the image becomes less noisy in the production model is different from that of the pre-production unit, so naturally, he just had to verify it. Supposedly it’s not dual ISO, but whatever it is, when the ISO is increased beyond four stops from the base ISO of any of the picture profiles (or even Standard) on the a7s III, the image cleans up dramatically. The base ISO for S-log is 640 and S-log2 and S-log3 now get cleaner 1/3 stop sooner, or at ISO 12800. Cine2, whose base ISO is 50, is much cleaner at ISO 1000 than at ISO 800 and HLG, with a base ISO of 100, switches at ISO 2000.

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